Stresses in Ultrasonically Assisted Turning

Abstract:

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Ultrasonically assisted turning (UAT) is a novel material-processing technology, where
high frequency vibration (frequency f ≈ 20kHz, amplitude a ≈15μm) is superimposed on the
movement of the cutting tool. Advantages of UAT have been demonstrated for a broad spectrum of
applications. Compared to conventional turning (CT), this technique allows significant
improvements in processing intractable materials, such as high-strength aerospace alloys,
composites and ceramics. Superimposed ultrasonic vibration yields a noticeable decrease in cutting
forces, as well as a superior surface finish. A vibro-impact interaction between the tool and
workpiece in UAT in the process of continuous chip formation leads to a dynamically changing
stress distribution in the process zone as compared to the quasistatic one in CT. The paper presents
a three-dimensional, fully thermomechanically coupled computational model of UAT incorporating
a non-linear elasto-plastic material model with strain-rate sensitivity and contact interaction with
friction at the chip–tool interface. 3D stress distributions in the cutting region are analysed for a
representative cycle of ultrasonic vibration. The dependence of various process parameters, such as
shear stresses and cutting forces on vibration frequency and amplitude is also studied.

Abstract: Ultrasonic vibration is applied to diamond turning of special stainless steel to decrease
diamond tool wear and improve the surface quality of the workpieces. It reviews the principle of
diamond turning of special stainless steel by applying ultrasonic vibration combined with gas shield.
Compared with the ordinary machining method, cutting temperature and cutting force are greatly
reduced when machining by application of ultrasonic vibration, and the appetency between a
diamond tool and Ferrous atom of a workpiece is also minimized as gas shield application. The
Experiments of cutting special stainless steel workpieces show that the surface roughness Ra is less
than 0.15μm and flank wear-width is less than 5μm when cutting distance is up to 2000m. It takes
research on the effect of cutting parameters to surface roughness and tool wear. The experiment
result shows that the amplitude is the most important factor which effects tool wear and surface
roughness most.

Abstract: Ultrasonic machining (USM) is a mechanical material removal process used to erode holes and cavities in hard or brittle work pieces by using shaped tools, high-frequency mechanical motion, and an abrasive slurry. There are many physical signals in the ultrasonic machining which are related with the material removal rate, machining accuracy, and surface finish. So how to measure and control these signals with accuracy is very important. The aim of the paper is to summarize different kinds of physical signals and the methods of measuring and controlling them in ultrasonic machining.

Abstract: Ultrasonic machining has been proven to be a promising machining method on hard and brittle materials. However, due to the absence of high power ultrasonic machine tools, reported studies on ultrasonic machining were mainly concerned of relatively small hole drilling of the given materials. In the present work, with the development of the higher power Rotary Ultrasonic Machine Tool, two kinds of ultrasonic face machining with free abrasives, namely, Non-rotating Ultrasonic Machining with Free Abrasives (NRUSM) and Rotary Ultrasonic Machining with Free Abrasives (RUSM) are designed and comparatively conducted for the red granite, which is a typical hard-to-machine natural material. The effects of static force, spindle speed and amplitude of ultrasonic vibration on the performance of the machining are evaluated in terms of the material removal rate and surface quality. Experimental results indicate that ultrasonic machining is effective for face milling of the stone material with the designed machine tool. Furthermore, machining performances in RUSM are superior to those in NRUSM.

Abstract: This paper proposes to use a method of ultrasonic milling on the composite materials processing, we mainly studies the effect of the length of the tool rod, tool rod diameter on the acoustic resonant frequency, amplitude, to ensure processing quality and improving the tool's vibration effect.

Abstract: Ultrasonic-vibration-assisted micro-cutting of Ti-6Al-4V was simulated by finite element analysis software ADVANTEDGE. During the micro-cutting of Ti-6Al-4V the cutting forces were compared between conventional and ultrasonic-vibration-assisted method. In the ultrasonic-vibration-assisted micro-cutting process different frequency and amplitude were applied on the cutting tool. The influences of frequency and amplitude were analyzed. The cutting temperature increases with the increase of the amplitude, and the cutting temperature decreases with the increase of frequency. By using the simulation method the appropriate amplitude and frequency data can be obtained.